How can i export my 3D animation for 3D video?
In that case, here-


Looks like it works in Cycles and Eevee, but the rendered viewport display in Cycles is very broken, and has been a bug since March 2019; https://developer.blender.org/T62582
It does render (F12) OK by the looks of it.
It outputs 2 images from the L/R cameras in 'Stereo 3D' mode, so you'll have to join them into a single Anaglyph image.
If you use 'MultiView' mode it will output an Anaglyph image, but you need 2 cameras in the scene, with '_L' and '_R' suffixes on their names, and you'll have to manually set their position / convergence.

Cheers
Mark